1. Field of the Invention
The present invention relates to an inkjet image forming method.
2. Description of the Related Art
An inkjet recording method using an ultraviolet curable component is widely used due to advantages such as rapid curing and robustness of the images formed. Of these, an aqueous UV inkjet system in which an ink component is dissolved and dispersed in an aqueous medium can reduce the load of the pile height, which is a drawback in most inkjet technologies.
However, if the water content of the ink component is not reduced to a predetermined level, the polymerization efficiency is considerably reduced. For this reason, a certain period of time is required for drying the water content, flow or spotting interference of the image is likely to occur before drying is completed, and it is difficult to obtain high-resolution images in some cases.
As approaches for realizing images with even higher quality, adjusting the physical properties of an ink composition such as viscosity or surface tension depending on the recording medium in order to control the penetration of the ink into the recording medium is a known technique. For example, it is believed that formation of images with high quality and good film physical properties after curing can be realized when the content of a polymerizable compound is from 30% by mass to 70% by mass and the viscosity of an ink is from 1 mPa·s to 30 mPa·s (at 35° C. or higher) (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 2004-189930). In addition, in order to suppress flowing and spotting interference of images before polymerization and curing are completed, a technique in which the components of an ink composition are aggregated by a two-liquid reaction has been disclosed (see, for example, JP-A No. 10-287035).
Further, as an apparatus-based approach for obtaining images with high quality, it is well known that it is important to maintain a predetermined relative position between a recording medium and an inkjet head. For this reason, it is known that the recording medium can be adhered to an apparatus that maintains the relative position between the recording medium and the head (for example, a back-up roller, a platen roller, a conveyance stage, a conveyance cylinder/a drum and the like) and conveyed using a roller pressing device, a absorbing device or an electrostatic suction-holding device. In particular, a suction-holding device is considered to be effective in conveying a recording medium having a large area.